How BestBuilders costs a job and matches a builder

The cost model

Every cost range on BestBuilders is produced by BestBuilders’ 2026 regional cost model. It has two parts. National cost guides give a baseline for materials and labour on a given job at a given specification. A regional labour index then scales the labour element for the area, because a day of a plasterer’s time is not priced the same in Sunderland as it is in Surrey.

The output is a range, not a number, and the width of the range is deliberate: two identical-sounding jobs can differ by a third once access, condition and finish are taken into account. When a page shows a figure for a particular town, that is the regional model applied to that town’s labour index — it is not a survey of local quotes.

What the model cannot tell you

It cannot see your house. It does not know whether the wall is solid or cavity, whether the drains run where the extension wants to go, or whether the existing wiring is anywhere near current standards. It also assumes a straightforward job with normal access. Anything unusual — listed buildings, conservation areas, poor ground, tight terraces — will sit above the range, sometimes well above it. Treat the range as the point at which to start being suspicious of a quote, in either direction, not as the price.

How matching works

When you request quotes, we match your enquiry on two things: the trade the job needs and the area you are in. You are introduced to up to three businesses that cover your postcode and take on that type of work. Nobody is placed first because they pay more; the fee a business pays for an introduction is the same regardless of position, and it does not depend on whether you hire them. Enquiries are handled through our own network and, where that cannot cover a job, passed to an external lead-generation partner, as described on how we get paid.

Checks before a builder is listed

The checks we run before a business joins the network are described on our about page. They are checks at the point of joining, not a continuous audit, which is why every guide on this site tells you to ask for a current insurance certificate and recent local work yourself before you sign anything. A check we ran last year is not a substitute for one you run this week.

Town and coverage figures

Where a page says we cover a number of towns, that is the number of towns for which the regional cost model has a labour index and for which the matching service is available. It is not a count of builders, and we do not publish builder counts by town because they change too often to be reliable.

Reviewing the numbers

The cost model is refreshed when its inputs change, and every cost page shows when it was last updated. If a figure looks out of line with quotes you have actually received, we want to know — real quotes are the best check on a model there is. Use the contact page.

BestBuilders editorial team · Last updated: 2 September 2026 · Next scheduled review: December 2026